Known in the art are magnetically controlled contacts made as ferromagnetic plates rigidly fixed in a support and overlapping each other at their free ends which will come closer to one another when the current flowing through a magnetizing coil grows from zero to a certain value and diverge when it continues growing (see, for example, U.S. Pat. No. 3,551,860).
A variation of the magnetic field intensity will result in a change of the gap between the ferromagnetic plates and, consequently, of the intercontact capacitance. The technique based on the use of the intercontact capacitance of the ferromagnetic plates as a parameter specifying the magnitude of a magnetic field intensity suffers from a number of drawbacks caused by the fact that with shifts of the plates the intercontact capacitance will vary in a non-linear way and at a low multiplicity factor. Besides, the absolute values of this capacitance are quite small (from 0.5 to 3.0 pF) and therefore their measurement requires that high frequencies should be used.
One of the known designs that is the closest to the one proposed herein relates to a device for converting a magnetic field intensity into an electric signal which comprises movable elements made as ferromagnetic plates rigidly fixed in supports so that their free ends overlap each other and an element for sensing the relative displacement of the free ends of the ferromagnetic plates, the element being connected to a measuring circuit. The displacement of the free ends of the ferromagnetic plates is measured with the use of photodetector elements, such as a photomultiplier and an illumination lamp, mounted at opposite sides of the gap between the overlapping ends of the ferromagnetic plates. In such devices the magnetic field intensity is converted into a current flowing through a photodetector element.
(See, for instance, Zaretskas V.-S.S., Ragulskene V. L. "Mercury commutator elements for automatic devices". Energia, 1971, p. 51).
However, the use of such devices as a means for converting the intensity of a magnetic field into an electric value requires a stable power supply, a dustless environment and precise adjustment of the ferromagnetic plates with respect to the illuminator-photodetector axis. Negligence to these requirements tends to reduce the reliability of such converters. Besides, their conversion range is limited when the size of ferromagnetic plates is increased.